1. Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, HR-10000 Zagreb, Croatia, Division of Molecular Medicine, Rudjer Bošković Institute, Bijenička 54, P.O.B. 1016, HR-10001 Zagreb, Croatia, and Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium